1. Field of the Invention
This invention relates to an improvement in an integrated fluid coking and gasification process in which cracking catalyst particles are added to the fluid coker.
2. Description of the Prior Art
Integrated fluid coking and gasification processes are known. See, for example, U.S. Pat. Nos. 3,661,543; 3,702,516 and 3,759,676, the teachings of which are hereby incorporated by reference.
A coking process is known in which coking is conducted in the presence of added hydrogen and a solid particulate contact material which may be bauxite, silica, or silica-alumina and which may further contain a hydrogenation component. See U.S. Pat. No. 2,888,395.
It is known to coke a heavy carbonaceous material in the presence of an alkali metal compound. The resulting coke, after partial gasification, is recycled to the coking zone. See U.S. Pat. No. 3,803,023.
A fluid coking process is known in which tar sand oil is coked. Fines from the cyclone to the low temperature burner with some of the coarser solids from the burner are regenerated in a fluid bed and used as cracking catalyst in the coking reactor. See U.S. Pat. No. 3,278,412.
An integrated coking and steam gasification process is known in which the coker feedstock is treated in the coker in the presence of a supported Group VB, VIIB or VIII metal oxide steam gasification catalyst. See U.S. Pat. No. 3,726,791.
It is known to scrub flue gas containing cracking catalyst with a heavy hydrocarbon oil which is subsequently used as feed for a fluid coker. See British Pat. No. 762,831.
It has now been found that the addition of a cracking catalyst to the coker feedstock and recycling the partially gasified catalyst-containing coke to the vapor phase product of the coking zone will provide advantages that will become apparent in the ensuing description.